Mascara brush



FIG. 1 is a perspective top, front and side elevation view showing the new design.

FIG. 2 is a side elevation view thereof, the other side, top and bottom views being the same; and,

FIG. 3 is a front end view thereof.

The broken lines in FIGS. 1-2 depict a rear portion of the brush which forms no part of the claimed design. 

CLAIM The ornamental design for a mascara brush, as shown and described. 